/*** Eclipse Class Decompiler plugin, copyright (c) 2016 Chen Chao (cnfree2000@hotmail.com) ***/
package com.appcore.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class AuthCodeUtil {
	private static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
	private static final String SESSION_KEY_BM_CODE = "SESSION_KEY_BM_CODE";
	private static Random random = new Random();

	public static void createAuthCodeAndOutput(int wide, int high, int size,
			HttpServletRequest request, HttpServletResponse response)
			throws IOException {
		response.setHeader("Pragma", "no-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0L);
		response.setContentType("image/gif");

		String authCode = createAuthCode(size);

		SessionManager.setAttribute(request, "SESSION_KEY_BM_CODE", authCode);

		OutputStream os = null;
		try {
			os = response.getOutputStream();
		} catch (IOException e) {
			e.printStackTrace();
		}

		outputImage(wide, high, os, authCode);
	}

	public static boolean checkAuthCode(String authCode,
			HttpServletRequest request, HttpServletResponse response)
			throws IOException {
		String sessionAuthCode = (String) SessionManager.getAttribute(request,
				"SESSION_KEY_BM_CODE");

		return (authCode.equalsIgnoreCase(sessionAuthCode));
	}

	public static String createAuthCode(int authSize) {
		return createAuthCode(authSize, "23456789ABCDEFGHJKLMNPQRSTUVWXYZ");
	}

	public static String createAuthCode(int authSize, String sources) {
		if ((sources == null) || (sources.length() == 0)) {
			sources = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
		}
		int codesLen = sources.length();
		Random rand = new Random(System.currentTimeMillis());
		StringBuilder authCode = new StringBuilder(authSize);
		for (int i = 0; i < authSize; ++i) {
			authCode.append(sources.charAt(rand.nextInt(codesLen - 1)));
		}
		return authCode.toString();
	}

	public static void outputImage(int wide, int high, File outputFile,
			String code) throws IOException {
		if (outputFile == null) {
			return;
		}
		File dir = outputFile.getParentFile();
		if (!(dir.exists()))
			dir.mkdirs();
		try {
			outputFile.createNewFile();
			FileOutputStream fos = new FileOutputStream(outputFile);
			outputImage(wide, high, fos, code);
			fos.close();
		} catch (IOException e) {
			throw e;
		}
	}

	public static void outputImage(int wide, int high, OutputStream os,
			String code) throws IOException {
		int w = wide;
		int h = high;
		int authSize = code.length();
		BufferedImage image = new BufferedImage(w, h, 1);
		Random rand = new Random();
		Graphics2D g2 = image.createGraphics();
		g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
				RenderingHints.VALUE_ANTIALIAS_ON);
		Color[] colors = new Color[5];
		Color[] colorSpaces = { Color.WHITE, Color.CYAN, Color.GRAY,
				Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE, Color.PINK,
				Color.YELLOW };

		float[] fractions = new float[colors.length];
		for (int i = 0; i < colors.length; ++i) {
			colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
			fractions[i] = rand.nextFloat();
		}
		Arrays.sort(fractions);
		g2.setColor(Color.GRAY);
		g2.fillRect(0, 0, w, h);
		Color c = getRandColor(200, 250);
		g2.setColor(c);
		g2.fillRect(0, 2, w, h - 4);

		Random random = new Random();
		g2.setColor(getRandColor(160, 200));
		for (int i = 0; i < 20; ++i) {
			int x = random.nextInt(w - 1);
			int y = random.nextInt(h - 1);
			int xl = random.nextInt(6) + 1;
			int yl = random.nextInt(12) + 1;
			g2.drawLine(x, y, x + xl + 40, y + yl + 20);
		}

		float yawpRate = 0.05F;
		int area = (int) (yawpRate * w * h);
		for (int i = 0; i < area; ++i) {
			int x = random.nextInt(w);
			int y = random.nextInt(h);
			int rgb = getRandomIntColor();
			image.setRGB(x, y, rgb);
		}

		shear(g2, w, h, c);

		g2.setColor(getRandColor(100, 160));
		int fontSize = h - 4;
		Font font = new Font("Fixedsys", 1, fontSize);
		g2.setFont(font);
		char[] chars = code.toCharArray();
		for (int i = 0; i < authSize; ++i) {
			AffineTransform affine = new AffineTransform();
			affine.setToRotation(0.7853981633974483D * rand.nextDouble()
					* ((rand.nextBoolean()) ? 1 : -1), w / authSize * i
					+ fontSize / 2, h / 2);
			g2.setTransform(affine);
			g2.drawChars(chars, i, 1, (w - 10) / authSize * i + 5, h / 2
					+ fontSize / 2 - 10);
		}

		g2.dispose();
		ImageIO.write(image, "jpg", os);
	}

	private static Color getRandColor(int fc, int bc) {
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

	private static int getRandomIntColor() {
    int[] rgb = getRandomRgb();
    int color = 0;
    for (int c : rgb) {
      color <<= 8;
      color |= c;
    }
    return color;
  }

	private static int[] getRandomRgb() {
		int[] rgb = new int[3];
		for (int i = 0; i < 3; ++i) {
			rgb[i] = random.nextInt(255);
		}
		return rgb;
	}

	private static void shear(Graphics g, int w1, int h1, Color color) {
		shearX(g, w1, h1, color);
		shearY(g, w1, h1, color);
	}

	private static void shearX(Graphics g, int w1, int h1, Color color) {
		int period = random.nextInt(2);

		boolean borderGap = true;
		int frames = 1;
		int phase = random.nextInt(2);

		for (int i = 0; i < h1; ++i) {
			double d = (period >> 1)
					* Math.sin(i / period + 6.283185307179586D * phase / frames);
			g.copyArea(0, i, w1, 1, (int) d, 0);
			if (borderGap) {
				g.setColor(color);
				g.drawLine((int) d, i, 0, i);
				g.drawLine((int) d + w1, i, w1, i);
			}
		}
	}

	private static void shearY(Graphics g, int w1, int h1, Color color) {
		int period = random.nextInt(40) + 10;

		boolean borderGap = true;
		int frames = 20;
		int phase = 7;
		for (int i = 0; i < w1; ++i) {
			double d = (period >> 1)
					* Math.sin(i / period + 6.283185307179586D * phase / frames);
			g.copyArea(i, 0, 1, h1, 0, (int) d);
			if (borderGap) {
				g.setColor(color);
				g.drawLine(i, (int) d, i, 0);
				g.drawLine(i, (int) d + h1, i, h1);
			}
		}
	}

	public static void main(String[] args) throws IOException {
		File dir = new File("D:/verifies");
		int w = 300;
		int h = 80;
		for (int i = 0; i < 50; ++i) {
			String authCode = createAuthCode(4);
			File file = new File(dir, new StringBuilder().append(authCode)
					.append(".jpg").toString());
			outputImage(w, h, file, authCode);
		}
	}
}